Plastic articles made from recycled medical and other plastic waste

ABSTRACT

Blends of recycled plastic materials and plastic products made therefrom are provided. The blends combine a high fraction of recycled medical waste with mixed recycled plastics, such as polyolefins or carpet waste. Also provided are methods for processing a heterogeneous waste stream such as medical waste to yield a homogenous material capable of blending with other materials and extrusion to form useful plastic products such as structural materials and consumer articles.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Divisional application of U.S. patent applicationSer. No. 15/413,638, entitled “PLASTIC ARTICLES MADE FROM RECYCLEDMEDICAL AND OTHER PLASTIC WASTE”, filed on Jan. 24, 2017, which is acontinuation of PCT/US2017/012059, filed 3 Jan. 2017 and entitled“Plastic Articles Made from Recycled Medical and Other Plastic Waste”,which claims the priority of U.S. Provisional Application No.62/273,533, filed 31 Dec. 2015 and entitled “Plastic Articles Made fromRecycled Medical and Other Plastic Waste”, and of U.S. ProvisionalApplication No. 62/301,259, filed 29 Feb. 2016 and entitled “PlasticArticles Made from Recycled Medical and Other Plastic Waste”. Allapplications are hereby incorporated by reference in their entireties.

BACKGROUND

Medical waste contains a variety of materials, especially plastics, butalso fibrous materials such as paper, which can be recycled to yielduseful products and to reduce the accumulation of such waste inlandfills or the need for incineration which causes pollution.Nevertheless, medical waste is a very heterogeneous material, whichmakes it difficult to recycle as is or to blend with other materials toproduce a homogeneous product. There is a need to develop uses forrecycled medical waste and other recycled plastic materials, includingmethods for their processing and recycling.

SUMMARY OF THE INVENTION

The invention provides blends of recycled plastic materials and plasticproducts made therefrom. The blends combine a high fraction of recycledmedical waste with mixed recycled plastics, such as polyolefins orcarpet waste. The invention further provides methods for processing aheterogeneous waste stream to yield a homogenous material capable ofblending with other materials and extrusion to form useful plasticproducts such as structural materials and consumer articles.

One aspect of the invention is a blend of recycled plastics containingat least about 40% by weight of recycled medical waste, or anotherheterogeneous recycled material, and at least about 20% by weight of oneor more other recycled plastics. The blend can further contain one ormore additives, such as blending agents, colorants, binders, or fillers.One embodiment of the blend contains about 70 wt % recycled medicalwaste and about 30% of one or more other recycled plastics. Anotherembodiment contains about 50 wt % recycled medical waste and about 50%other recycled plastic. In yet another embodiment the other recycledplastic includes recycled carpet. In certain embodiments, the blendcontains one or more of polyethylene, polypropylene, and polyester. Incertain embodiments, the blend is formed into a plastic product, such asa lumber product, landscape product, deck product, fence product, orrailroad tie.

Another aspect of the invention is a method of making a recycled plasticmaterial. The method includes the steps of: (a) providing a recycledmedical waste material and one or more recycled plastic materials; (b)sterilizing the recycled medical waste material; (c) grinding andblending the product of step (b); (d) blending the product of step (c)with the one or more recycled plastic materials; and (e) optionallypelletizing or grinding the product of step (d). In embodiments, themethod further includes: (f) forming a melt from the product of step (d)or step (e); and (g) forming the melt into a plastic product, such as byextrusion or molding.

The invention can further be summarized through the following list ofembodiments.

-   1. A blend of recycled plastics comprising at least about 40% by    weight of recycled medical waste and at least about 20% by weight of    one or more other recycled plastics.-   2. The blend of embodiment 1, further comprising one or more    additives selected from blending agents, colorants, and fillers.-   3. The blend of embodiment 2 comprising ethylene vinyl acetate as a    binder and carbon black as a colorant.-   4. The blend of any of the preceding embodiments, wherein the    recycled plastics comprise about 70 wt % recycled medical waste and    about 30% of one or more other recycled plastics.-   5. The blend of any of embodiments 1-3, wherein the recycled    plastics comprise about 50 wt % recycled medical waste and about 50%    other recycled plastic.-   6. The blend of embodiment 4 or 5, wherein the other recycled    plastic comprises recycled carpet.-   7. The blend of any of the preceding embodiments that comprises two    or more polymers selected from the group consisting of polyethylene,    polypropylene, and polyester.-   8. The blend of embodiment 7 that comprises polyethylene,    polypropylene, and polyester.-   9. The blend of embodiment 7 further comprising one or more polymers    selected from the group consisting of polyvinyl chloride,    polycarbonate, and polystyrene.-   10. The blend of any of the preceding embodiments that is in    granular or powder form.-   11. The blend of any of the preceding embodiments that is extruded    or molded to form a plastic product.-   12. The blend of embodiment 11, wherein the plastic product is    selected from the group consisting of lumber products, landscape    products, deck products, fence products, and railroad ties.-   13. A method of making a recycled plastic material, the method    comprising the steps of:

(a) providing a recycled medical waste material and one or more recycledplastic materials;

(b) sterilizing the recycled medical waste material;

(c) shredding and blending the product of step (b);

(d) blending the product of step (c) with the one or more recycledplastic materials; and

(e) optionally pelletizing or grinding the product of step (d).

-   14. The method of embodiment 13 further comprising:

(f) forming a melt from the product of step (d) or step (e); and

(g) extruding the melt to form a plastic product.

-   15. The method of embodiment 14, wherein the plastic product is a    plastic lumber product.-   16. The method of any of embodiments 13-15, further comprising    between steps (b) and (c) the step of:

(b1) removing metal objects from the sterilized medical waste material.

-   17. The method of embodiment 13, wherein the blending of step (d)    combines about 50 wt % medical waste with about 50 wt % of    non-medical waste recycled plastic material.-   18. The method of embodiment 13, wherein the blending of step (d)    combines about 60 wt % medical waste with about 40 wt % of    non-medical waste recycled plastic material.-   19. The method of embodiment 13, wherein the blending of step (d)    combines about 70 wt % medical waste with about 30 wt % of    non-medical waste recycled plastic material.-   20. The method of any of embodiments 13-19, wherein the blending of    step (d) includes adding about 1 wt % of a blending agent.-   21. The method of any of embodiments 13-20, wherein the blending of    step (d) includes adding a colorant.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a flow diagram of a method of processing recycled medicalwaste, blending it with another recycled plastic material, and forming aplastic product from the blend.

FIG. 2 shows transmission infrared spectra of a material containingabout 70% recycled medical waste and about 30% mixed recycled plastics(in solid form and ground form), together with standard referencematerials (SRM) of polyethylene (PE), polypropylene (PP), and polyester.

FIG. 3 shows transmission infrared spectra of a material containingabout 30% recycled medical waste and about 70% mixed recycled plastics(in solid form and ground form), together with standard referencematerials (SRM) of PE, PP, and polyester.

DETAILED DESCRIPTION OF THE INVENTION

The invention provides plastic materials made using recycled medicalwaste and methods of processing medical waste or other heterogeneouswaste streams to form homogenous composite plastic materials in raw formor as finished products.

Medical waste for use in the invention is typically in the form ofbagged or boxed plastic, paper, and metal articles that have contactedpatient materials or samples, or that have been implanted in a patient,and are therefore suspected of potential contamination with pathogens ortoxic materials used in medical procedures, such as pharmaceutical ordiagnostic agents. The waste is very heterogeneous and may containneedles, tubing, plastic syringes, and the like. Medical waste can alsoinclude materials used in the production of biotechnology products, suchas cell culture materials, filters, and chromatography columns. Theheterogeneity of recycled medical waste makes it nearly impossible touse to create useful homogeneous materials or new articles withoutsignificant processing and blending with other materials. In addition torecycling medical waste, the methods of the present invention also canbe employed with heterogeneous waste streams, such as waste materialscontaining a combination of plastic, fibrous materials such as paper,cardboard, or wood, and small metal objects. Preferably theheterogeneous waste contains at least about 20%, 30%, 40%, 50%, 60%, or70% by weight of plastic material, and only small amounts, such as lessthan about 50%, 40%, 30%, 20%, 15%, 10%, 5%, 2%, or 1% by weight offibrous material, and preferably containing only small amounts of metalor other hard materials, such as less than about 20%, 15%, 10%, 5%, 2%,or 1% by weight. Optionally, the waste can be hand selected or certaintypes of materials selectively removed by attendants who load thematerial into the process.

FIG. 1 shows a diagram of an embodiment of a recycling method of thepresent invention. Received medical waste is first sterilized prior tofurther handling. Metal objects are advantageously removed early in theprocess, so as to avoid interference with machinery or their accidentalinclusion in final product. For example, ferromagnetic materials can beremoved by exposing them to a magnet, which separates them from thenon-ferromagnetic material. Then, the medical waste is shredded intosmall pieces so as to enhance further processing. One or more grindingprocesses also can be performed prior to or after shredding. After thematerial has been reduced to small pieces, it is blended, preferablyafter heating to melt the low melt plastics in the mixture. Afterblending, the material can be cooled and granulated to produce a rawmaterial that can be stored and sold for other uses, or can be directlyadmixed with other materials, such as recycled nonmedical plastic waste,and/or with new (i.e., non-recycled) polymer materials. Blending can beenhanced by the addition of a polymer blending agent. The combined wastematerials, and optionally non-waste materials, are then compounded andcan be formed into a pelleted or powdered raw material. The raw materialcan then be further processed, such as by melting and extrusion ormolding to form a plastic product. Once a melt is formed containing themedical waste, the melt can be processed to form commercial objects,such as structural lumber or building materials, railroad ties,landscaping materials, or other objects using any standard method forcreating plastic articles.

Sterilization may include application of heat, chemicals, and/orradiation. For example, the sterilization process can include theaddition of CaO to recycled medical waste. The sterilization processpreferably results in at least a log 6 kill factor. After sterilization,undesired materials may be removed by magnetic separation, visualinspection and manual removal, or by other means. For example, theprocess can use rollers, inspection, and electromagnets for separatingferrous and/or nonferrous metals from the recycled medical waste.

Mechanical mixing steps used to combine and reduce the size of objectsfound in the medical waste stream can include various mixing andprocessing steps, such as grinding, shredding, heating, cooling,melting, or compounding of a melt with other materials. The medicalwaste material can be densified so as to render it suitable for gravityfeed processing. Fibrous or other filler materials can be added toimprove mechanical properties. High-speed grinding can be performed.Blended medical waste can be heated at one or more temperatures toachieve a suitable viscosity. Blends can be melted and extruded at atemperature such as 300° F., 310° F., 320° F., 330° F., 340° F., 350°F., 360° F., 370° F., 380° F., 390° F., 400° F. or 410° F. A compoundingextruder can be used in the extrusion process. In certain embodiments,the extrusion process produces an extruded material containing a core ofhigh melt polymers and an outer layer of lower melt polymers surroundingthe core.

The invention includes compositions of matter in the form of rawmaterials and finished products such as lumber, landscaping timbers,railroad ties, decking material, plastic-containing furniture,playground structures, and construction materials such as buildingframing materials, structural members, roofing, and flooring. In apreferred embodiment, the surface of products made according to theinvention are paintable. For example, the surface can have a suitablelevel of hydrophobicity, wettability, and surface charge as to render itadherent to oil- or water-based paint applied as a spray, or by brush,roller, or dipping. Products can also be colored by inclusion of acolorant (e.g., carbon black) or dye in the blend, rendering the productmade therefrom colored throughout.

The materials of the invention can contain a combination of polymersobtained from processed and sterilized medical waste, optionallycombined with additional polymers sourced from other recycled materials,such as carpet waste, or new polymer materials. In embodiments, themedical waste comprises or consists essentially of polypropylene (PP)and/or polyethylene (PE, which may include high density polyethylene(HDPE)). In certain embodiments, carpet waste comprises or consistsessentially of polyethylene terephthalate (PET) and or PP. Additionalpolymers that can be added as new materials or in the form of recycledplastics include polyamide (PA), nylon, polycarbonate (PC),polyvinylchloride (PVC), polystyrene (PS), polyester, liquid crystalpolymers (LCP), and mixtures thereof, as well as copolymers such asethylene vinyl acetate (EVA) useful to promote blending.

In certain embodiments, materials of the invention include recycledmedical waste in an amount by weight of at least 20%, 30%, 40%, 45%,48%, 49%, 49.5%, 50%, 51%, 55%, 60%, 65%, 70%, 75%, or 80%. In certainembodiments, materials of the invention include one or more otherrecycled plastic materials, or new, non-recycled plastic materials, inan amount by weight of at least 20%, 30%, 40%, 45%, 48%, 49%, 49.5%,50%, 51%, 55%, 60%, 65%, 70%, 75%, or 80%. Materials of the inventionalso can include one or more blending agents (e.g., EVA) in an amount byweight of 0.1-10%, such as 0.5%, 1%, 1.5%, or 2%. The materials of theinvention further can contain one or more types of filler or inclusions,such as polymer fibers, carbon fibers, graphene, metals, inorganicoxides, nanoparticles, nanotubes, and the like. Colorants such as carbonblack or dyes also can be added. Preferred blends according to theinvention include a blend of 20-80% by weight recycled medical waste and20-80% by weight recycled polyolefin (primarily a blend of PE and PP),such as 50% recycled medical waste and 50% recycled polyolefin, or 55%recycled medical waste and 45% recycled polyolefin, or 60% recycledmedical waste and 40% recycled polyolefin, or 65% recycled medical wasteand 35% recycled polyolefin, or 70% recycled medical waste and 30%recycled polyolefin, or 75% recycled medical waste and 25% recycledpolyolefin, or 80% recycled medical waste and 20% recycled polyolefin,or 45% recycled medical waste and 55% recycled polyolefin, 40% recycledmedical waste and 60% recycled polyolefin, or 30% recycled medical wasteand 70% recycled polyolefin. Other preferred blends include a blend of20-80% recycled medical waste and 20-80% recycled carpet material, suchas motor vehicle trunk liner material (a blend of approximately 45% PPand 55% PET), such as 50% recycled medical waste and 50% recycled carpetmaterial, or 55% recycled medical waste and 45% recycled carpetmaterial, or 60% recycled medical waste and 40% recycled carpetmaterial, or 65% recycled medical waste and 35% recycled carpetmaterial, or 70% recycled medical waste and 30% recycled carpetmaterial, or 75% recycled medical waste and 25% recycled carpetmaterial, or 80% recycled medical waste and 20% recycled carpetmaterial, or 45% recycled medical waste and 55% recycled carpetmaterial, 40% recycled medical waste and 60% recycled carpet material,or 30% recycled medical waste and 70% recycled carpet material. For theabove described blends, 100% refers to the weight of recycled plasticmaterials in the blend. In addition, small amounts (less than about 1%,less than about 2%, or less than about 5% by weight of the finalcomposition) of one or more colorants and one or more blending agentsand one or more fillers can be added.

Materials of the invention can be provided in different forms, includingpellets, powder, as well as extruded structural members or lumber in theform of boards, sheets, or any other desired shape. The materials can beproduced in a variety of different particle sizes, useful as a rawmaterial for different purposes, such as a mesh size of 5, 6, 7, 8, 9,10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, or 100 mesh.

EXAMPLES Example 1. Preparation of Plastic Blends Containing RecycledMedical Waste

Four different blends of recycled plastic materials were prepared. Thecomposition of the blends is shown in Table 1 below. In Table 1, 100%represents the total of all recycled plastic materials, withoutincluding additives such as blending agents or colorants.

TABLE 1 Recycled Plastic Blends. Recycled Medical Mixed Recycled BlendWaste Plastic Recycled Carpet A 70 wt % 30 wt % 0 B 50 wt % 0 50 wt % C50 wt % 50 wt % 0 D 0 70 wt % 30 wt %

The recycled medical waste was prepared by sterilizing the medicalwaste, removing metals, blending the medical waste with the indicatedamounts of other recycled plastic materials. The mixed recycled plasticcontained about 30 wt % polyolefin (e.g., PE and PP) with the remainderbeing predominately PC, PVC, and/or PET. The recycled carpet was motorvehicle trunk liner cuttings containing approximately 45 wt % PP and 55wt % PET. The final material of each blend additionally containedapproximately 2% carbon black as colorant, as well as 1% or less of EVAas blending agent.

FIG. 2 shows transmission infrared spectra of Blend A in solid form andground form, together with standard reference materials (SRM) of PE, PP,and polyester. The blend apparently contained contributions from PE, PP,and polyester, in the relative amounts of PE>PP>polyester. The spectraand composition of ground and solid materials appeared essentiallyidentical.

FIG. 3 shows transmission infrared spectra of Blend D in solid form andground form, together with standard reference materials (SRM) of PE, PP,and polyester. TL refers to recycled trunk liner (carpet) material. Theblend showed contributions from PE, PP, and polyester, with a higheramount of polyester than Blend A. The relative amounts appeared to bePE>polyester>PP. Since PET was present in the carpet material, and PETis a type of polyester, at least a portion of the polyester spectrumobserved in the blend was probably due to PET.

The Blends A and D, whose IR spectra are shown in FIGS. 2 and 3, wereashed to remove all organic material, leaving only inorganic filler orresidue, which was identified and quantified by energy dispersive X-rayspectroscopy (EDXS). The results are shown in Table 2 below for thematerial extruded in the form of lumber as well as extruded, regroundmaterial.

TABLE 2 X-Ray Spectroscopy. Blend A Blend A Blend D Blend D 70% 70% 70%70% Med Waste Med Waste HDPE HDPE 30% HDPE 30% HDPE 30% TL 30% TL Oxide(Regrind) (Lumber) (Regrind) (Lumber) Na2O 4.1 3.9 2.3 2.6 MgO 3.1 3.22.6 2.9 Al2O3 5.3 5.6 5.1 4.8 SiO2 23.8 22.8 9.3 6.6 P2O5 0.8 0.8 1.52.1 SO3 2.8 2.1 3.7 2.7 Cl2O7 20.2 21.1 0.4 0.1 K2O 0.4 0.4 0.1 0.1 CaO28.1 29.3 23.8 15.2 TiO2 3.2 3.2 42.1 36.0 FeO 1.5 1.6 1.4 1.4 Cu2O — —0.3 0.5 NiO — — — — ZnO 0.6 0.4 0.4 0.3

Example 2. Preparation and Testing of Plastic Lumber Products ContainingRecycled Medical Waste

Blends A-C described in Example 1 were extruded to form plastic lumberproducts in different formats, including nominal 2×6 inch boards (actualdimensions 1.5 inches×5.5 inches×108 inches length) and nominal 4×4 inchposts (actual dimensions 3.5 inches×3.5 inches×108 inches). Theseproducts were subjected to mechanical testing according to standard ASTMprotocols, and the results are described below.

ASTM D-6117-13e1, Method A, Fastener Withdrawal

Fastenal Premium All Purpose Deck Screws (#9, 11×2.5 in) were installedin plastic lumber products on a face, edge, and cut end of each lumberspecimen. The specimen was then conditioned at the indicated conditionsfor 24-48 hours prior to testing. Increasing load was applied to theinstalled screws until either the screw or the lumber substrate failed,and the load at time of failure is reported in Table 3 as the average of10 determinations (average of 30 determinations for the 73° F., 50% RHcondition).

TABLE 3 Screw Withdrawal Test. Lumber Avg. Maximum Load Blend FormConditioning (lb) A 2 × 6 in 73° F., 50% RH 1410 (side) 24-48 hr   1436(edge) 817 (end) A 2 × 6 in 99° F., 50% RH 1140 (side) 12 hr A 2 × 6 in−4° F., 12 hr 1727 (side) A 2 × 6 in 70° F., water soak 1419 (side) 24hr B 2 × 6 in 73° F., 50% RH 1410 (side) 24-48 hr   1429 (edge) 927(end) B 2 × 6 in 99° F., 50% RH 1207 (side) 12 hr B 2 × 6 in −4° F., 12hr 1777 (side) B 2 × 6 in 70° F., water soak 1438 (side) 24 hr C 2 × 6in 73° F., 50% RH 1782 (side) 24-48 hr   1799 (edge) 1358 (end) C 2 × 6in 99° F., 50% RH 1449 (side) 12 hr C 2 × 6 in −4° F., 12 hr 1702 (side)C 2 × 6 in 70° F., water soak 1685 (side) 24 hr A 4 × 4 in 73° F., 50%RH 1203 (side) 24-48 hr   1156 (edge) 613 (end) A 4 × 4 in 99° F., 50%RH 995 (side) 12 hr A 4 × 4 in −4° F., 12 hr 1691 (side) A 4 × 4 in 70°F., water soak 1179 (side) 24 hr B 4 × 4 in 73° F., 50% RH 1561 (side)24-48 hr   1491 (edge) 1002 (end) B 4 × 4 in 99° F., 50% RH 1194 (side)12 hr B 4 × 4 in −4° F., 12 hr 1775 (side) B 4 × 4 in 70° F., water soak1356 (side) 24 hr

Fastener stability was best for Blend C in the 2×6 format, while for the4×4 format fastener stability was better for Blend B than for Blend A.In both formats, lowering the temperature increased fastener stability,and raising the temperature weakened fastener stability. Soaking inwater had little or no effect.

ASTM D-6109-13, Method B, Flexural Properties Under Third Point Loading

Plastic lumber specimens were conditioned for at least 88 hours at 73°F., 50% relative humidity (RH). Load was increased until the boardfailed due to flexural rupture. For the 2×6 lumber the support span was88.00 inches, the load span was 29.31 inches, and the load was appliedto the nominal 2 inch face. For the 4×4 lumber the support span was56.00 inches and the load span was 18.64 inches. Results presented inTable 4 are average values from five specimens.

TABLE 4 Third Point Loading Test. Maximum Maximum Flexural Load StrainStrength MOR Blend Lumber Form (lbf) (in/in) (psi) B 2 × 6 in 1179 0.0051767 C 2 × 6 in 851 0.008 1509 A 4 × 4 in 1436 0.010 1854 B 4 × 4 in1179 0.006 1531

Flexural stability was greatest for Blend A, and least for Blend C.

ASTM D-6108-13, Method B, Compressive Properties

Lumber specimens were subjected to compressive loading perpendicular tothe length of the boards. Load was applied to the nominal 2 inch facesof the 2×6 lumber. Load was applied until 3% strain was achieved.Results presented in Table 5 are average values from five specimens.

TABLE 5 Compressive Properties. Stress at Modulus of Secant 3% StrainElasticity Modulus Blend Lumber Form (psi) (psi) (psi) B 2 × 6 in 3089125464 126421 C 2 × 6 in 3134 117303 116128 A 4 × 4 in 1661 72586 73347B 4 × 4 in 2144 78044 77585

Resistance to compression was similar for Blends A-C.

ASTM D-6111-13a, Bulk Density and Specific Gravity

The bulk density and specific gravity of plastic lumber specimens weremeasured by water displacement at 74° F. The lumber was preconditionedaccording to ASTM D618 prior to testing. One inch pieces of the lumberspecimens were cut with a miter saw, and cut edges were covered withpackaging tape. Results presented in Table 6 are average values fromfive specimens.

TABLE 6 Specific Gravity and Density. Bulk Specific Bulk Density BlendLumber Form Gravity (lb/ft³) A 2 × 6 in 1.00 62.48 B 2 × 6 in 1.11 69.33C 2 × 6 in 0.93 58.22 A 4 × 4 in 0.95 59.16 B 4 × 4 in 1.06 66.22

The bulk specific gravity and density were greatest for Blend B.

As used herein, “consisting essentially of” allows the inclusion ofmaterials or steps that do not materially affect the basic and novelcharacteristics of the claim. Any recitation herein of the term“comprising”, particularly in a description of components of acomposition or in a description of elements of a device, can beexchanged with “consisting essentially of” or “consisting of”.

While the present invention has been described in conjunction withcertain preferred embodiments, one of ordinary skill, after reading theforegoing specification, will be able to effect various changes,substitutions of equivalents, and other alterations to the compositionsand methods set forth herein.

What is claimed is:
 1. A blend of recycled plastics comprising at leastabout 40% by weight of recycled medical waste and at least about 20% byweight of one or more other recycled plastics.
 2. The blend of claim 1,further comprising one or more additives selected from blending agents,colorants, and fillers.
 3. The blend of claim 2 comprising ethylenevinyl acetate as a binder and carbon black as a colorant.
 4. The blendof claim 1, wherein the recycled plastics comprise about 70 wt %recycled medical waste and about 30% of one or more other recycledplastics.
 5. The blend of claim 1, wherein the recycled plasticscomprise about 50 wt % recycled medical waste and about 50% otherrecycled plastic.
 6. The blend of claim 5, wherein the other recycledplastic comprises recycled carpet.
 7. The blend of claim 1 thatcomprises two or more polymers selected from the group consisting ofpolyethylene, polypropylene, and polyester.
 8. The blend of claim 7 thatcomprises polyethylene, polypropylene, and polyester.
 9. The blend ofclaim 7 further comprising one or more polymers selected from the groupconsisting of polyvinyl chloride, polycarbonate, and polystyrene. 10.The blend of claim 1 that is in granular or powder form.
 11. The blendof claim 1 that is extruded or molded to form a plastic product.
 12. Theblend of claim 11, wherein the plastic product is selected from thegroup consisting of lumber products, landscape products, deck products,fence products, and railroad ties.